DESCRIPTION: (provided by the applicant) This two-year investigation is designed to increase our understanding of the precise etiologic and developmental processes that influence adolescent alcohol and other drug use. The proposed study significantly extends a program of prospective research to determine the efficacy of Life Skills Training (LST), a school-based, competence enhancement, drug abuse prevention program targeted to middle school populations. Secondary analyses will be conducted using data from three randomized, school-based, prevention trials including a study of primarily white middle-class youth (N=5800), one containing predominantly Hispanic youth (N=3500) and a third comprised mainly of black inner-city youth (N=5900). Evidence has been obtained from each sample regarding the efficacy of the LST intervention in reducing cigarette, alcohol, and marijuana use with follow-up assessments conducted anywhere from three to six or more years following implementation. An essential next step is to conduct manipulation checks to determine if the reductions in drug use are brought about in the manner hypothesized and whether a multi-component intervention strategy is essential to achieve this goal. The study will specifically focus on determining the relative efficacy of three theoretically driven prevention approaches including: social skills/social competence, personal skills and self-management, and normative education (including strategies to alter cognitions regarding the social acceptability of drug use and information regarding the harmful effects of drug use). A primary analytic focus includes the use of structural equation modeling to test mediation as well as hierarchical linear modeling to control for potential clustering effects that arise from randomization of schools to experimental conditions. An important feature of this research is the use of multiple datasets that share a common assessment of key psychosocial risk mechanisms involved in the etiology of adolescent drug use and the ability to test alternative risk mechanisms that may operate specifically in ethnic minority populations. This study has the potential of informing prevention science with regard efficacious intervention strategies that extend to a wide range of ethnic groups during the critical and formative years of adolescence.